This is a multi-disciplinary program project, with research activities in the areas of gonorrhea, syphilis, and chlamydial, ureaplasma, and cytomeagalovirus infections. Emphasis in on both basic microbiology and immunology, and applied problems such as organism identification and clinical epidemiology. Four integrated projects focus on the gonococcus, including basic genetics, biochemistry and antigenicity of the cell surface; virulence and host immune response; and importance of cell-wall deficient forms in human disease. Two integrated projects examine the basic physiology, pathogenicity, and immunology of T. pallidum. Two interrelated projects examine the biology of persistent genital chlamydia infection; new methods for detection of Chlamydia and ureaplasma in tissues, and for quantiation of specific antibody against these organisms; and the frequency of genital Chlamydia and unrealplasma in neonatal pneumonias. One project probes the clinical epidemiology of sexually-transmitted cytomegalovirus infections, and the possibility and consequences of sexual CMV transmission in an animal model.